CN105542019B - Resistant dextrin and preparation method thereof - Google Patents

Abstract

The present invention relates to a kind of resistant dextrin and preparation method thereof.The resistant dextrin, molar content≤7.0% of molar content≤4.5%, DP3 of DP1 molar content≤1%, DP2, average degree of polymerization is 6~12, pH value 3.0~6.0, dietary fiber molar content >=85%.The invention further relates to the preparation method of above-mentioned resistant dextrin.Dextrinization reaction is divided into two stages by the present invention first using starch as raw material, it is effectively guaranteed that the degree of polymerization of polymerisation, while reducing the generation of side reaction, greatly reduces the difficulty of purifying subsequent treatment.

Description

Resistant dextrin and its preparation method

technical field

The invention relates to a resistant dextrin and a preparation method thereof, belonging to the technical field of food additive production.

Background technique

With the improvement of people's living standards, many people have symptoms of hyperlipidemia, high blood pressure, and hyperglycemia, commonly known as the "three highs", and they tend to become younger and younger. The World Health Organization has clearly stated that the first line of defense in the prevention and treatment of cardiovascular disease is to reduce and control the "three highs". Among these people with three highs, except for those who are more serious and need to cooperate with drug treatment, most of them can be adjusted through diet therapy and other methods to avoid the side effects of drugs.

Dietary fiber is a carbohydrate that cannot be digested by the human body. It is divided into two categories: insoluble and water-soluble fiber. In the "Twelfth Five-Year Plan", the country advocates the development of dietary fiber applications to curb the potential harm caused by chronic diseases to Chinese people. The daily intake of dietary fiber recommended by relevant international organizations is: the recommended standard of the American Cancer Prevention Association is per person per day 30-40 grams, the recommended standard of the European Community Food Science Committee is 30 grams per person per day. The Chinese Nutrition Society recommends that the daily dietary fiber intake for the human body is 25-35 grams.

Resistant dextrin is a low-calorie dextran, a low-molecular water-soluble dietary fiber prepared from natural starch. Compared with other dietary fiber products, resistant dextrin has good acid and heat stability and high digestion resistance. Acceptability, low glycemic index, low insulin index, low calorie, prevent dental caries and other excellent properties.

Chinese patent document CN 104403009 A (application number 201410671093.0) discloses a method for preparing resistant dextrin, which includes the following steps: using acid-treated starch as a raw material, using sea sand as a heat transfer medium, and carrying out the process under high temperature conditions. Pyrolysis reaction to obtain crude pyrodextrin, which is then refined to obtain resistant dextrin products.

Chinese patent document CN103725732A (application number 201310743226.6) discloses a method for comprehensive utilization of wheat starch C to prepare resistant dextrin, comprising the following steps: (1) using wheat starch C starch slurry as raw material, adjusting the pH with hydrochloric acid, sealing and acidifying (2) drying the acidified starch slurry after centrifugation; (3) pyrolysis in a roller heating furnace; (4) cooling to room temperature, adding an appropriate amount of distilled water, and preparing an emulsion with a certain concentration range; (5) The double-enzyme synergistic method of liquefaction and saccharification is carried out simultaneously; (6) add activated carbon for decolorization and suction filtration to obtain the sample liquid; (7) carry out alcohol precipitation on the feed liquid, centrifuge, and recycle the supernatant by distilling alcohol, and air-dry the precipitation to obtain the content The resistance dextrin is 85%-90%, and the product yield is 80%-90%.

The above-mentioned preparation method still has the disadvantages of high bitterness, deliquescence, and poor fluidity of the product, and cannot be widely used in food and health products, especially in the fields of high-end food and health products.

Contents of the invention

Aiming at the deficiencies of the prior art, the invention provides a resistant dextrin and a preparation method thereof. The resistant dextrin prepared by the invention is not easy to deliquescence, has good taste and fluidity, and is convenient for wide application in the fields of food and health care products, especially high-end food and health care products.

Glossary

DP refers to the degree of polymerization (Degree of Polymerization), which is an index to measure the molecular size of a polymer, based on the number of repeating units, that is, the average number of repeating units contained in the polymer macromolecular chain.

DP1 is a macromolecule with a degree of polymerization of 1, DP2 is a macromolecule with a degree of polymerization of 2, and DP3 is a macromolecule with a degree of polymerization of 3.

In order to realize the present invention, the present invention adopts following technical scheme:

A resistant dextrin, characterized in that: the molar percentage of DP1 ≤ 1%, the molar percentage of DP2 ≤ 4.5%, the molar percentage of DP3 ≤ 7.0%, the average degree of polymerization is 6-12, the pH The value is 3.0-6.0, and the molar percentage of dietary fiber is ≥85%.

The preparation method of the above-mentioned resistant dextrin comprises the following steps:

(1) adding an acid solution to the starch at a ratio of 0.1% to 0.5% by mass, and stirring evenly to obtain a reaction material;

(2) Heat up the reaction material prepared in step (1) to 80°C to 120°C, react under normal pressure for 2 to 4 hours to obtain the initial reaction material, and then add Stir the acid solution evenly, raise the temperature to 140-200°C, and conduct a gelatinization reaction under normal pressure for 15-30 minutes to obtain coarse dextrin;

(3) Add deionized water to the dextrin crude material prepared in step (2), adjust the sugar concentration to 40-45 wt%, and keep it under acidic hydrolysis at a temperature of 80-100°C for 1-2 hours to obtain the hydrolyzed liquid;

(4) The hydrolyzate obtained in step (3) is decolorized, separated, concentrated, purified, and dried to obtain resistant dextrin.

Preferably according to the present invention, the acid in the step (1) and step (2) is an edible acid; further preferably, the acid is selected from one of citric acid, malic acid, hydrochloric acid, phosphoric acid, sulfuric acid or A combination of two or more.

Preferably according to the present invention, the mass concentration of the acid in the step (1) and step (2) is 0.08-0.12%.

Preferably according to the present invention, the decolorization in the described step (4), the steps are as follows:

Add activated carbon at 0.5% to 1.5% of the dry basis mass, heat and stir for 25 to 35 minutes, and then filter to obtain a feed solution with a light transmittance ≥ 95%.

Preferably according to the present invention, the detachment in the described step (4), the steps are as follows:

Adjust the temperature of the feed liquid before entering the column to 35-55°C, and the pH of the feed liquid out of the column to 4.0-5.0 to obtain a ionizing liquid with a conductance of <100 μs/cm and a light transmittance of ≥98%;

Preferably according to the present invention, the concentration in the step (4) adopts six-effect concentration, and concentrates to a solid content of 50-60% by mass.

Preferably according to the present invention, the purification in the step (4) includes chromatographic purification, secondary decolorization, secondary separation, and secondary concentration.

Further preferably according to the present invention, the chromatographic purification is to adjust the pH to 6.0-7.0, and then carry out chromatographic purification through the chromatographic separation system. The operating conditions of the chromatographic separation are operating pressure 0.2-0.35MPa, temperature 50-70°C, water consumption ratio 1 : (1.2～1.5), feeding 1.2～1.5m ³ per hour.

According to a further preferred embodiment of the present invention, the secondary decolorization is to add activated carbon at 0.5% to 1.5% of the dry basis mass, heat and stir for 25 to 35 minutes, and then filter;

According to a further preferred method of the present invention, the steps of said secondary separation are as follows:

Adjust the temperature of the feed liquid before entering the column to 35-55°C, and the pH of the feed liquid out of the column to be 4.0-5.0 to obtain a secondary ion exchange liquid with a conductance of <100 μs/cm and a light transmittance of ≥98%;

According to a further preferred aspect of the present invention, the secondary concentration: use six-effect concentration to concentrate to a solid content of 50-60% by mass, pH 4.0-5.0, and obtain a conductivity < 100 μs/cm, light transmittance ≥ 98 %;

Preferably according to the present invention, the drying in the step (4) is belt-type vacuum drying until the moisture mass percentage is ≤6%.

The above-mentioned raw materials are common commercially available products in the field, and the process steps can be operated according to the routine in the field unless otherwise specified.

Beneficial effect

1. The present invention uses starch as a raw material, divides the dextrinization reaction into two stages for the first time, effectively guarantees the degree of polymerization of the polymerization reaction, reduces side reactions at the same time, and greatly reduces the difficulty of subsequent purification treatment;

2. The present invention adopts non-enzyme catalyzed reaction, namely does not need to add biological enzyme in the whole process of reaction, utilizes the acidic environment that itself exists to hydrolyze naturally in the hydrolysis process, adopts non-enzyme catalyzed reaction to simplify the reaction process on the one hand, on the other hand Greatly reduce the production cost and reduce the difficulty of subsequent purification treatment;

3. The present invention overcomes the disadvantages of many side reactions in the original process, high bitterness of the product, easy deliquescence, and poor fluidity. The molar percentage of the prepared resistant dextrin DP1 is ≤ 1%, and the molar percentage of DP2 is ≤ 4.5%, the molar percentage of DP3 is ≤7.0%, the average degree of polymerization is 6-12, the pH value is 3.0-6.0, and the molar percentage of dietary fiber is ≥85%, which makes the product have good taste and fluidity, and is easy to use in food , health products, especially high-end food and health products are widely used.

detailed description

The technical solutions of the present invention will be further described below in conjunction with the examples, but the protection scope of the present invention is not limited thereto.

The starch described in the examples was purchased from Shandong Fuyang Biotechnology Co., Ltd.;

Malic acid was purchased from Nanjing Guohai Biological Engineering Co., Ltd.;

Citric acid was purchased from Shandong Lemon Biochemical Co., Ltd.

Example 1

The preparation method of resistant dextrin comprises the steps of:

(1) Add malic acid solution to the starch at a ratio of 0.2% by mass, and stir evenly to obtain a reaction material;

(2) The reaction material obtained in step (1) is warmed up to 85° C., and reacted under normal pressure for 2.5 hours to obtain the initial reaction material, then add malic acid solution in a ratio of 2% by mass percent of the initial reaction material, and stir evenly. Raise the temperature to 160°C, under normal pressure, gelatinize for 20 minutes to obtain crude dextrin;

(3) Add deionized water to the crude dextrin material prepared in step (2), adjust the sugar concentration to 41 wt%, and heat-preserve and acidify it for 1.2 hours at a temperature of 85°C to obtain a hydrolyzate;

(4) The hydrolyzed solution prepared in step (3) is added activated carbon by 0.7% of the dry basis mass, and after insulated and stirred for 30min, it is filtered to obtain a feed solution with a light transmittance of 96%;

Then adjust the temperature of the feed liquid before entering the column to be 41° C., and the pH of the feed liquid out of the column is 4.2, so as to obtain an ionizing liquid with a conductance of 80 μs/cm and a light transmittance of 99%.

Then adopt six-effect concentration, concentrate to solid matter percentage content and be 52%;

After chromatographic purification, secondary decolorization, secondary separation, secondary concentration, and belt vacuum drying until the moisture content is 5%, the resistant dextrin is obtained.

The chromatographic purification is to adjust the pH to 6.5, and then perform chromatographic purification through the chromatographic separation system. The operating conditions of the chromatographic separation are operating pressure 0.2MPa, temperature 50-70°C, water consumption ratio 1:1.2, and feed 1.2m ³ per hour;

The secondary decolorization is to add activated carbon according to 0.6% of the dry basis mass, and then filter after insulated and stirred for 30 minutes;

Described secondary separation, the steps are as follows:

Adjust the temperature of the feed liquid before entering the column to 39°C, and the pH of the feed liquid out of the column to 4.2, to obtain a secondary ion exchange liquid with a conductance of 90 μs/cm and a light transmittance of 99%.

The secondary concentration: using six-effect concentration, concentrated to a solid content of 55% by weight, pH: 4.5, conductance<80μs/cm, light transmittance≥99%;

The mass concentration of the acid in the step (1) and the step (2) is 0.1%.

After testing, the molar percentage of the prepared resistant dextrin DP1 is 0.3%, the molar percentage of DP2 is 4.1%, the molar percentage of DP3 is 6%, the average degree of polymerization is 7, pH5.0, The mass percentage content of dietary fiber is 88%.

Example 2

The preparation method of resistant dextrin comprises the steps of:

(1) Add citric acid solution to the starch at a ratio of 0.1% by mass, stir evenly, and prepare the reaction material;

(2) The reaction material that step (1) is made is warmed up to 80 ℃, reacts 2h under normal pressure, makes primary reaction material, then adds citric acid solution and stirs evenly by the ratio of initial reaction material mass percentage 2%, is heated up to 150°C, under normal pressure conditions, gelatinization reaction for 17min, to obtain crude dextrin;

(3) Add deionized water to the crude dextrin material prepared in step (2), adjust the sugar concentration to 42 wt%, and heat-preserve the acidic hydrolysis at a temperature of 85° C. for 1.5 hours to obtain a hydrolyzed solution;

(4) The hydrolyzed solution prepared in step (3) is added activated carbon by 0.7% of the dry basis mass, and after insulated and stirred for 30min, it is filtered to obtain a feed solution with a light transmittance of 96%;

Then adjust the temperature of the feed liquid before entering the column to be 40°C, and the pH of the feed liquid out of the column is 4.5, so as to obtain a ion exchange liquid with a conductance of 90 μs/cm and a light transmittance of 98%.

Then adopt six-effect concentration to concentrate to a solid content of 55% by weight;

After chromatographic purification, secondary decolorization, secondary separation, secondary concentration, and belt vacuum drying to a moisture content of 5%, the resistant dextrin is obtained.

The chromatographic purification is to adjust the pH to 6.5, and then perform chromatographic purification through the chromatographic separation system. The operating conditions of the chromatographic separation are operating pressure 0.35MPa, temperature 70°C, water consumption ratio 1:1.5, and feed 1.5m ³ per hour;

The secondary decolorization is to add activated carbon according to 0.7% of the dry mass, and then filter after insulated and stirred for 30 minutes;

Described secondary separation, the steps are as follows:

Adjust the temperature of the feed liquid before entering the column to 40°C, and the pH of the feed liquid out of the column to 4.5 to obtain a secondary ion exchange liquid with a conductance of 80 μs/cm and a light transmittance of 99%.

The secondary concentration: using six-effect concentration, concentrated to a solid content of 58% by mass, pH 4.5, conductance 90 μs/cm, and light transmittance 99%;

Preferably according to the present invention, the mass concentration of the acid in the step (1) and step (2) is 0.08%.

After testing, the molar percentage of the prepared resistant dextrin DP1 is 0.2%, the molar percentage of DP2 is 4.3%, the molar percentage of DP3 is 6.5%, the average degree of polymerization is 7, and the pH value is 4.0. Dietary fiber mass percentage content 90%.

Example 3

The preparation method of resistant dextrin comprises the steps of:

(1) adding hydrochloric acid solution to the starch at a ratio of 0.3% by mass, stirring evenly to obtain a reaction material;

(2) The reaction material prepared in step (1) is warmed up to 100° C., and reacted for 3 hours under normal pressure to obtain the initial reaction material, then add hydrochloric acid solution in a ratio of 6% by mass percent of the initial reaction material and stir evenly, and heat up to 160 ℃, under normal pressure conditions, gelatinization reaction for 22min, to obtain crude dextrin;

(3) Add deionized water to the dextrin coarse material prepared in step (2), adjust the sugar concentration to 43wt%, and heat-preserve the acidic hydrolysis at a temperature of 91° C. for 1.5 hours to obtain a hydrolyzate;

(4) The hydrolyzate prepared in step (3) was added activated carbon by 1.0% of the dry basis mass, and after insulated and stirred for 30 minutes, filtered to obtain a feed liquid with a light transmittance of 96%;

Then adjust the temperature of the feed liquid before entering the column to be 45°C, and the pH of the feed liquid out of the column to be 4.5, so as to obtain an ionizing liquid with a conductance of <100 μs/cm and a light transmittance of ≥98%;

Then adopt six-effect concentration to concentrate to a solid content of 55% by weight;

After chromatographic purification, secondary decolorization, secondary separation, secondary concentration, and belt vacuum drying to a moisture content of 5%, the resistant dextrin is obtained.

The chromatographic purification is to adjust the pH to 6.5, and then perform chromatographic purification through the chromatographic separation system. The operating conditions of the chromatographic separation are operating pressure 0.3MPa, temperature 60°C, water consumption ratio 1:1.3, and feed 1.4m ³ per hour;

The secondary decolorization is to add activated carbon according to 1% of the dry mass, and after stirring for 30 minutes, filter;

Described secondary separation, the steps are as follows:

Adjust the temperature of the feed liquid before entering the column to 50°C, and the pH of the feed liquid out of the column to 4.5 to obtain a secondary ion exchange liquid with a conductivity of 85 μs/cm and a light transmittance of 99%.

The secondary concentration: using six-effect concentration, concentrated to a solid content of 60% by mass, pH 4.5, conductance 90 μs/cm, and light transmittance 99%;

The mass concentration of the acid in the step (1) and step (2) is 0.12%.

After testing, the molar percentage of the prepared resistant dextrin DP1 is 0.5%, the molar percentage of DP2 is 4.1%, the molar percentage of DP3 is 6.0%, the average degree of polymerization is 9, pH 3.5, diet The fiber mass percentage is 86%.

Example 4

The preparation method of resistant dextrin comprises the steps of:

(1) Add a mixed solution of citric acid and malic acid in a volume ratio of 1:1 to the starch at a ratio of 0.5% by mass, and stir evenly to obtain a reaction material;

(2) The reaction material obtained in step (1) is heated up to 120° C., and reacted for 2 hours under normal pressure to obtain the initial reaction material, and then add citric acid and malic acid according to the volume ratio of the initial reaction material mass percentage of 10%. Stir the 1:1 mixed solution evenly, heat up to 200°C, and conduct a gelatinization reaction for 30 minutes under normal pressure to obtain coarse dextrin;

(3) adding deionized water to the crude dextrin material prepared in step (2), adjusting the sugar concentration to 45 wt%, and keeping the temperature at 100° C. for 2 hours for acidic hydrolysis to obtain a hydrolyzed solution;

(4) The hydrolyzate prepared in step (3) is added into activated carbon by 1.5% of the dry basis mass, and after insulated and stirred for 35min, filter to obtain a feed liquid with a light transmittance of 95%;

Then adjust the temperature of the feed liquid before entering the column to be 55°C, and the pH of the feed liquid out of the column to be 5.0, to obtain an ionizing liquid with a conductance of 95 μs/cm and a light transmittance of 98%.

Then adopt six-effect concentration to concentrate to a solid content of 60% by weight;

After chromatographic purification, secondary decolorization, secondary separation, secondary concentration, and belt vacuum drying to a moisture content of 6%, the resistant dextrin is obtained.

The chromatographic purification is to adjust the pH to 7.0, and then perform chromatographic purification through the chromatographic separation system. The operating conditions of the chromatographic separation are operating pressure 0.25MPa, temperature 65°C, water consumption ratio 1:1.4, and feed 1.3m ³ per hour;

The secondary decolorization is to add activated carbon according to 1.5% of the dry mass, and then filter after insulated and stirred for 35 minutes;

Described secondary separation, the steps are as follows:

Adjust the temperature of the feed liquid before entering the column to 55°C, and the pH of the feed liquid out of the column to 5.0 to obtain a secondary ion exchange liquid with a conductivity of 95 μs/cm and a light transmittance of 99%.

The secondary concentration: using six-effect concentration, concentrated to a solid content of 56% by mass, pH 5.0, conductance 95 μs/cm, and light transmittance 99%;

The mass concentration of the acid in the step (1) and step (2) is 0.09%.

After testing, the molar percentage of the prepared resistant dextrin DP1 is 0.5%, the molar percentage of DP2 is 4.1%, the molar percentage of DP3 is 6.0%, the average degree of polymerization is 11, pH5.0, The mass percentage content of dietary fiber is 91%.

Example 5

The preparation method of resistant dextrin comprises the steps of:

(1) adding phosphoric acid solution to the starch at a ratio of 0.1% by mass, stirring evenly to obtain a reaction material;

(2) The reaction material that step (1) is made is warmed up to 80 ℃, reacts 2h under normal pressure, makes initial reaction material, then adds phosphoric acid solution and is warming up to 140 ℃ by the ratio of initial reaction material mass percentage 1%, usually Under pressure conditions, the gelatinization reaction was carried out for 15 minutes, and the dextrin crude material was obtained;

(3) adding deionized water to the crude dextrin material prepared in step (2), adjusting the sugar concentration to 40 wt%, and keeping the temperature at 80° C. for 1 hour for acidic hydrolysis to obtain a hydrolyzed solution;

(4) The hydrolyzate prepared in step (3) was added activated carbon by 0.5% of the dry basis mass, and after insulated and stirred for 25 minutes, filtered to obtain a feed liquid with a light transmittance of 96%;

Then adjust the temperature of the feed liquid before entering the column to be 35° C., and the pH of the feed liquid out of the column is 4.0, so as to obtain an ionizing liquid with a conductance of 80 μs/cm and a light transmittance of 99%.

Then adopt six-effect concentration, and concentrate until the mass percent content of solid matter is 50%;

After chromatographic purification, secondary decolorization, secondary separation, secondary concentration, and belt vacuum drying to a moisture content of 6%, the resistant dextrin is obtained.

The chromatographic purification is to adjust the pH to 6.0, and then perform chromatographic purification through the chromatographic separation system. The operating conditions of the chromatographic separation are operating pressure 0.25MPa, temperature 55°C, water consumption ratio 1:1.25, and feed 1.25m ³ per hour;

The secondary decolorization is to add activated carbon according to 0.5% of the dry mass, and after stirring for 25 minutes, filter;

Described secondary separation, the steps are as follows:

Adjust the temperature of the feed liquid before entering the column to 35°C, and the pH of the feed liquid out of the column to 4.0 to obtain a secondary ion exchange liquid with a conductivity of 80 μs/cm and a light transmittance of 99%.

The secondary concentration: using six-effect concentration, concentrated to a solid content of 53% by weight, pH 4.0, conductance 80 μs/cm, and light transmittance 99%;

The mass concentration of the acid in the step (1) and step (2) is 0.11%.

After testing, the molar percentage of the prepared resistant dextrin DP1 is 1%, the molar percentage of DP2 is 4.5%, the molar percentage of DP3 is 7.0%, the average degree of polymerization is 6, and the pH value is 3.5. The dietary fiber content is 89%.

Comparative example 1

The traditional process of preparing resistant dextrin is as follows:

Add 0.05-0.5% hydrochloric acid solution by weight to the starch, mix evenly, filter, pre-dry, pulverize with a powder machine and pass through a 20-60 mesh sieve, mix the edible oil and the pre-dried starch evenly, and then add the mixture The temperature in the reaction vessel is raised to 150-250°C for acid-heat reaction for 10-120 minutes, and the crude indigestible dextrin is obtained after the reaction is completed, and the crude indigestible dextrin is refined to obtain the indigestible dextrin product;

The mass concentration of the hydrochloric acid is 0.1%.

The pre-drying temperature is 80° C. to 110° C., and the pre-drying is performed until the moisture content is less than 5 wt%.

The edible oil is edible soybean oil.

The added amount of the edible oil is 10-200% of the weight of the starch.

Comparative example 2

A method for preparing resistant dextrin, comprising the steps of:

(1) Add hydrochloric acid solution to starch in a proportion of 6.3% by mass and stir evenly, heat up to 160°C, and under normal pressure, gelatinize for 3 hours and 22 minutes to obtain coarse dextrin; stir evenly to obtain reaction material;

(3) Add deionized water to the dextrin coarse material prepared in step (2), adjust the sugar concentration to 43wt%, and heat-preserve the acidic hydrolysis at a temperature of 91° C. for 1.5 hours to obtain a hydrolyzate;

(4) The hydrolyzate prepared in step (3) was added activated carbon by 1.0% of the dry basis mass, and after insulated and stirred for 30 minutes, filtered to obtain a feed liquid with a light transmittance of 96%;

Then adjust the temperature of the feed liquid before entering the column to be 45°C, and the pH of the feed liquid out of the column to be 4.5, so as to obtain an ionizing liquid with a conductance of <100 μs/cm and a light transmittance of ≥98%;

Then adopt six-effect concentration to concentrate to a solid content of 55% by weight;

After chromatographic purification, secondary decolorization, secondary separation, secondary concentration, and belt vacuum drying to a moisture content of 5%, the resistant dextrin is obtained.

The chromatographic purification is to adjust the pH to 6.5, and then perform chromatographic purification through the chromatographic separation system. The operating conditions of the chromatographic separation are operating pressure 0.25MPa, temperature 55°C, water consumption ratio 1:1.25, and feed 1.25m ³ per hour;

The secondary decolorization is to add activated carbon according to 1% of the dry mass, and after stirring for 30 minutes, filter;

Described secondary separation, the steps are as follows:

Adjust the temperature of the feed liquid before entering the column to 50°C, and the pH of the feed liquid out of the column to 4.5 to obtain a secondary ion exchange liquid with a conductivity of 85 μs/cm and a light transmittance of 99%.

The secondary concentration: using six-effect concentration, concentrated to a solid content of 55% by mass, pH 4.5, conductance 90 μs/cm, and light transmittance 99%;

The mass concentration of the acid in the step (1) and the step (2) is 0.1%.

After testing, the prepared resistant dextrin has a DP1 of 2.5%, a DP2 of 8.1%, a DP3 of 12.0%, an average degree of polymerization of 15, a pH of 3.5, and a dietary fiber mass percentage of 62%.

Application example

Comparative example 1 and comparative example 2 products and the product made by embodiment 3 compare as follows through testing product index:

Dietary fiber content is tested according to the national standard "GB/T 5009.88-2008 Determination of Dietary Fiber in Food".

Table 1

DP1 DP2 DP3 Average degree of polymerization Dietary Fiber Content Comparative example 1 3.2% 8.5% 15.0% twenty one 58% Comparative example 2 2.5% 8.1% 12% 15 62 Example 3 0.5% 4.1% 6.0% 9 86%

From the above comparison, it can be seen that the content of the resistant dextrin product in Example 3 is much lower than that of the comparative examples DP1-DP3, and the low average degree of polymerization indicates that the reaction is more sufficient, the distribution of separation is more uniform, and the content of dietary fiber is higher at the same time. The advantages are obvious.

Comparative example 1 and the product applicability contrast that comparative example 2 product and embodiment 3 make are as follows:

The resistant dextrin product of Example 3 was compared with the products of Comparative Example and Comparative Example 2. The fluidity of the product was compared and evaluated using the index of angle of repose. The included angle, the fluidity is often expressed by the angle of repose, the smaller the angle of repose, the better the fluidity, otherwise the opposite.

Hygroscopicity (moisture absorption rate) is calculated according to the following formula:

Moisture absorption rate = (sample mass after moisture absorption - absolute dry sample mass) / absolute dry sample mass

The test results are shown in Table 2 below:

Table 2

As can be seen from the above data, Comparative Example 1 and Comparative Example 2 do not comply with the molar percentage of DP1 ≤ 1% due to DP1, DP2 and DP3, the molar percentage of DP2 ≤ 4.5%, and the molar percentage of DP3 ≤ 4.5%. 7.0% requirement, and the average polymerization degree does not meet the requirement of 6～12, so it is all significantly inferior to the product index of embodiment 3 in respects such as taste, fluidity, solubility, hygroscopicity.

Claims (12)

1. a kind of preparation method of resistant dextrin, it is characterised in that comprise the following steps：

（1）0.1%~0.5% ratio adds acid solution into starch by mass percentage, stirs, and reaction material is made；

（2）By step（1）Obtained reaction material is warming up to 80 DEG C~120 DEG C, and 2~4h is reacted under normal pressure, initial action material is made, so Acid solution is added in the ratio of initial action material mass percent 1%~10% to stir, be warming up to 140~200 DEG C, normal pressure bar afterwards Under part, dextrin coarse fodder is made in gelatinization 15~30min of reaction；

（3）To step（2）Deionized water is added in obtained dextrin coarse fodder, the sugared concentration of regulation is 40~45wt%, be 80 in temperature Acidic hydrolysis 1~2 hour is incubated under the conditions of~100 DEG C, hydrolyzate is made；

（4）By step（3）Obtained hydrolyzate is through decolouring, from friendship, concentration, purifying, dry, obtained resistant dextrin；

The Mole percent of molar content≤4.5%, DP3 of molar content≤1%, DP2 of the resistant dextrin DP1 contains Amount≤7.0%, average degree of polymerization is 6~12, pH value 3.0~6.0, dietary fiber molar content >=85%.

2. preparation method as claimed in claim 1, it is characterised in that the step（1）And step（2）In acid be selected from lemon Combination more than one or both of acid, malic acid, hydrochloric acid, phosphoric acid, sulfuric acid.

3. preparation method as claimed in claim 1, it is characterised in that the step（1）And step（2）In acid solution matter It is 0.08~0.12% to measure concentration.

4. preparation method as claimed in claim 1, it is characterised in that the step（4）In decolouring, step is as follows：

Added by the 0.5%~1.5% of butt quality after activated carbon, 25~35min of insulated and stirred, light transmittance >=95% is made in filtering Feed liquid.

5. preparation method as claimed in claim 1, it is characterised in that the step（4）In from friendship, step is as follows：

It is 35~55 DEG C to adjust the feed temperature into before post, goes out post material liquid pH 4.0~5.0, and the μ s/cm of conductance ＜ 100, light transmittance is made >=98% from hand over liquid.

6. preparation method as claimed in claim 1, it is characterised in that the step（4）In concentration be using six effect concentrate, It is 50~60% to be concentrated into solid quality degree.

7. preparation method as claimed in claim 1, it is characterised in that the step（4）In purifying include chromatography purity, two It is secondary decolourize, it is secondary from hand over, secondary concentration.

8. preparation method as claimed in claim 7, it is characterised in that the chromatography purity is tune pH6.0~7.0, Ran Houjing Chromatographic fractionation system carry out chromatography purity, chromatographic isolation service condition be 0.2~0.35MPa of operating pressure, 50~70 DEG C of temperature, Water consume compares 1:（1.2~1.5）, 1.2~1.5m is fed per hour³。

9. preparation method as claimed in claim 7, it is characterised in that the secondary decolourization be by butt quality 0.5%~ 1.5% adds after activated carbon, 25~35min of insulated and stirred, filtering.

10. preparation method as claimed in claim 7, it is characterised in that described secondary from friendship, step is as follows：

It is 35~55 DEG C to adjust the feed temperature into before post, goes out post material liquid pH 4.0~5.0, and the μ s/cm of conductance ＜ 100, light transmittance is made >=98% it is secondary from hand over liquid.

11. preparation method as claimed in claim 7, it is characterised in that the secondary concentration：Concentrated, be concentrated into using six effects Solid quality degree is 50~60%, pH4.0~5.0, and the μ s/cm of conductance ＜ 100, light transmittance >=98% is made.

12. preparation method as claimed in claim 1, it is characterised in that the step（4）In drying be dry through belt vacuum It is dry to biodiversity degree≤6%.